OperationResult class sealed

Base sealed class for operation results.

This follows the Result pattern (similar to Rust's Result<T, E>), providing type-safe error handling without exceptions.

Usage:

final result = manager.updateMinSdk(23);
switch (result) {
  case Success(:final message):
    print('Success: $message');
  case Failure(:final error):
    print('Error: $error');
}